Filter, in particular for the lubricating oil of an internal combustion engine

ABSTRACT

A filter, in particular for the lubricating oil of an internal combustion engine, which includes a pot-shaped filter housing ( 10 ), a support tube ( 11 ) disposed therein and a filter element ( 14 ) secured on the support tube ( 11 ). The filter element is essentially made up of a filtering material which is folded in a pleated manner and has plates ( 15  and  16 ) at its ends. The filter housing provides a direct seal between itself and a flange ( 19 ), and the support tube is provided with a screw-on thread ( 21 ).

BACKGROUND OF THE INVENTION

The invention relates to a filter, in particular for the lubricating oilof an internal combustion engine.

Such a filter is, for example, known from DE 41 39 680. This filter hasaccording to FIG. 1 of the publication, an annular filter cartridgewhich is pushed onto a central tube with the assistance of gaskets 18,19. The central tube is connected fast with a bell housing 11, by meansof which a simplification of the structural assembly can be achieved ina high degree of economy. The bell housing is attached, for example to amotor block, by means of an adapter 15. By using different adapters, aflexible utilization of the filter with different sizes of connectors ispossible.

However, the disclosed structure also has disadvantages. As a result ofthe use of the adapter, it becomes necessary to incur an additionalsealing expense in the form of gasket rings 14, 24. Also, the gaskets,which are used for sealing the filter cartridge, have a complexstructure, so that no standard parts can be used.

SUMMARY OF THE INVENTION

The invention therefore is addressed to the object of providing afilter, especially for lubricant oil of an internal combustion engine,which will consist of few parts and thus will be easy to service as wellas inexpensive. This object is achieved by the invention as describedand claimed hereinafter.

The substantial advantage of the invention is to be seen in the factthat the filter in the basic version consists of four component parts,namely a housing, a center tube, a metal-free cartridge and a gasket. Ina preferred manner the housing is an injection molded synthetic resinpart. This part is very inexpensive to manufacture and can also be made,for example, from recycled material.

The filter is provided with a replaceable filter element. The filterelement is merely pushed over the supporting tube and has a radialgasket.

The entire housing is open toward a flange. This means that no end plateclosing the pot-shaped housing is necessary. By the elimination of theend plate, direct access to the filter element is assured, so that itcan be replaced without special tools.

In one embodiment of the invention provision is made for the supporttube to be threaded into the housing or, when injection molded plasticis used, for it to be welded by ultrasound or high frequency oradhesively joined.

The filter element in one embodiment of the invention is provided withend plates which are made of nitrile rubber and thus have a highelasticity. In this way additional sealing means can be omitted. The endplates themselves produce a radial sealing of the filter element. In apreferred embodiment a filter element bypass valve can be arranged onthe supporting tube. The possibility also exists for arranging anon-return valve in the supporting tube. Both valves are of simpleconstruction and consist substantially of a valve spring and a valveplate.

Usually the filter element is mounted floatingly on the support tube,i.e. its axial position is defined by the abutment on the bottom of thehousing. For precise fixation of the filter element, a catch element canbe provided on the support tube, which prevents displacement of thefilter element. It is also possible to provide a sleeve or the like onthe support tube for the fixation of the filter element.

To prevent raw oil, i.e. oil that has not yet been filtered, fromflowing in reverse direction, the end plate facing the flange can beequipped with a non-return valve, for example in the form of a one-pieceprofile gasket. In this way the filter is effectively prevented fromrunning empty.

These and additional features of preferred embodiments of the inventionwill be found not only in the claims but also in the description and thedrawings, and the individual features can each be realized individuallyor together in the form of subcombinations in the embodiments of theinvention and in other fields, and can constitute advantageous as wellas independently patentable embodiments, for which protection is herebyclaimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be explained in further detail hereinafter withreference to illustrative embodiments.

FIG. 1 shows a sectional view of a simple filter,

FIG. 2 shows the simple filter depicted in FIG. 1 with additionalelements.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

The filter according to FIG. 1 comprises a pot-shaped housing 10. Intothis housing a support tube 11 is screwed. The housing carries a profilegasket 12 on the axial end facing a mounting flange. A filter element 14is pushed onto the support tube 11 which is provided with openings 13.This filter element 14 is comprised of a pleated filter material whichis provided at the ends with end plates 15 and 16. In conjunction withthe outer surface of the support tube the end plates form a radial sealat their inner annular opening and thereby seal the raw liquid area 17from the clean liquid area 18. The filter element 14 is merely slippedonto the support tube 11. The sealing areas of the end plates providefor a secure retention of the filter in the filter housing.

In FIG. 2 a filter with additional features is shown. The filter isfastened on a flange 19, a hollow screw 20 being provided on the flangewhich meshes with the thread 21 on the support tube 11. The introductionof the liquid to be cleaned takes place through the opening 22, and thereturn flow takes place through the already mentioned hollow screw 20and its opening 23.

In the support tube 11 is a filter element bypass valve 24 and aback-flow check valve 25. The check valve consists essentially of aspring 26 and a valve plate 27. A check valve for the raw liquid in theform of a sealing lip 28 is disposed on the filter element 14, i.e. onits end plate 16. Also, two removal tabs 29 and 30 are provided on theend plate 16. These facilitate the removal of the filter element 14. Thefilter element 14 can thus be pulled off from the support tube manuallyor with a simple tool.

The replacement of the filter element can be carried out in differentways. As already mentioned, it is possible to pull off the filterelement 14 from the support tube and replace it with a new one. Butthere is also the alternative possibility of releasing the connectionbetween the support tube 11 and housing 10, unscrewing the support tube,and pulling the filter element off at the opposite end of the supporttube. It also should be mentioned that there is also the possibility ofreplacing the entire filter with a new one. The used filter can bedelivered to a recycling plant.

What is claimed is:
 1. A filter comprising: a pot-shaped filter housing,a filter element support tube disposed in the filter housing, a returnflow check valve disposed in the support tube and having a spring and avalve plate, wherein said valve bears against a valve seat disposed insaid support tube, and a filter element arranged on the support tube,said filter element consisting essentially of a pleated annular filtermaterial with a pair of resilient end plates affixed to respective endfaces thereof, said filter element being pushed onto said support tubewith each of said end plates forming a radial seal with said supporttube, said support tube having an attachment thread which can be screwedonto a mating threaded portion on a mounting flange to attach the filterto the mounting flange, wherein the spring of said return check valve isaxially disposed between said valve plate and the mating threadedportion of said mounting flange, and said filter housing directlyreceiving a gasket for sealing said housing to the mounting flange.
 2. Afilter comprising: a pot-shaped filter housing, a filter element supporttube disposed in the filter housing, and a filter element arranged onthe support tube, said filter element consisting essentially of apleated annular filter material with a pair of resilient end platesaffixed to respective end faces thereof, one of the end plates includingan exposed major surface that axially faces an open end of said filterhousing, a removal tab fixedly attached onto said exposed major surfaceto facilitate removal of said filter element from the open end of saidpot shaped housing, said filter element being pushed onto said supporttube with each of said end plates forming a radial seal with saidsupport tube, said support tube having an attachment thread which can bescrewed onto a mating thread on a mounting flange to attach the filterto the mounting flange, and said filter housing directly receiving agasket for sealing said housing to the mounting flange.
 3. A filtercomprising: a pot-shaped filter housing, a filter element support tubedisposed in the filter housing, and a filter element arranged on thesupport tube, said filter element consisting essentially of a pleatedannular filter material with a pair of resilient end plates affixed torespective end faces thereof, one of the end plates including an exposedmajor surface axially facing an opening of said filter housing, said oneend plate having a radially outer peripheral edge positioned adjacent acylindrical inner surface portion of said filter housing, said filterelement being pushed onto said support tube with each of said end platesforming a radial seal with said support tube, and a sealing lip checkvalve comprising a resilient sealing lip attached to the exposed majorsurface of said one filter element, said sealing lip extending radiallyoutwardly from the radially outer peripheral edge of said one end capinto sealing contact with said cylindrical inner surface portion of thefilter housing, such that the resilient sealing lip is operable to admitunfiltered liquid from a supply line to a raw liquid chamber surroundingsaid filtering material and prevent back flow of the unfiltered liquidfrom the raw liquid chamber to the supply line, said support tube havingan attachment thread which can be screwed onto a mating thread on amounting flange to attach the filter to the mounting flange, and saidfilter housing directly receiving a gasket for sealing said housing tothe mounting flange, wherein during replacement of the filter element,the resilient sealing lip is removable along with the filter element asan integral unit from the support tube.